The objectives are: 1. to improve our isolation technique in order to obtain pure preparations of mucosal cells; 2. to determine the cellular and subcellular distribution of the olfactory receptors; 3. to identify the protein aggregate and polypeptides constituting the olfactory receptor sites. Separation of the mucosal cells will be done by improving our previous technique. An attempt will also be made to separate the cells by changing their physical properties. Preliminary results have shown a correlation between amino acid binding effectiveness to isolated olfactory cells and the electrophysiological activity of these amino acids. This will be used as the main criterion to assess the presence of a receptor in mucosal fractions. The cellular distribution of olfactory receptors will be determined on isolate and deciliated olfactory cells and on isolated cilia. The subcellular distribution of receptor sites will also be followed on cell subfractions. The identification of the protein aggregate constituting the receptor site will be performed by gel filtration.